Studies are being undertaken of the biochemical structure of muscle membranes isolated from rat fast and slow, innervated and denervated preparations. Polypeptide, lipid, and carbohydrate composition for surface membrane components are being examined in detail in addition to protein kinase, and adenylate cyclase activity. As a futher means of understanding the structure and function of excitable membranes, studies are in progress of red blood cell and muscle membranes of patients with myotonic muscular dystrophy, Duchenne muscular dystrophy, and myotonia congenita. Other experiments are examining the role of immune responses to the acetylcholine receptor in myasthenia gravis. BIBLIOGRAPHIC REFERENCES: Roses, Allen D. and Appel, Stanley H. Phosphorylation of Component a of the Human Erythrocyte Membrane in Myotonic Muscular Dystrophy. J. Membr. Biol., 20:51-58, 1975. Andrew, Clifford G., Almon, Richard R. and Appel, Stanley H. Macromolecular Characterization of Muscle Membranes: Endogeneous Membrane Kinase and Phosphorylated Protein Substrate from Normal and Denervated Muscle. J. Biol. Chem., 250:2973-3980, 1975.